A 301 redirect is an HTTP status code that tells browsers and search engines that a page has permanently moved to a new URL. When a user or bot visits the old URL, they are automatically redirected to the new one. For SEO purposes, 301 redirects pass approximately 90-99% of the original page's link equity (authority from backlinks) to the new URL. 301 redirects are used when permanently changing URL structures, migrating to a new domain, merging pages, or removing and replacing content.
301 redirects are essential during any URL structure change or site migration. Without them, backlinks pointing to old URLs become 404 errors, destroying the link equity those URLs had accumulated. A site migration without proper 301 redirects can cause severe ranking drops from which recovery takes many months. Proper redirect mapping — identifying every changed URL and creating the correct redirect — is the most important technical task in any URL-changing project.
301 redirect best practices
- Redirect old URLs to the most relevant new URL — not to the homepage if a more specific match exists
- Avoid redirect chains — A → B → C should be simplified to A → C (each hop loses a small amount of equity)
- Avoid redirect loops — A → B → A; these prevent pages from loading and are crawl budget wasters
- Implement HTTPS redirects — all HTTP URLs should 301 redirect to HTTPS equivalents
- Test all redirects after implementation — check the destination URL and response code for every redirect
- Monitor in Search Console — check for crawl errors and coverage issues after implementing redirects
- Keep redirects active — do not delete redirects; they can remain indefinitely at minimal server cost
A 301 redirect is permanent — it tells search engines that the old URL should be replaced by the new one in the index, and it passes link equity to the new URL. A 302 redirect is temporary — it tells search engines that the redirect may be reversed, so the original URL should remain indexed and link equity is not transferred. Most SEO redirects should be 301s. Use 302s only for genuinely temporary situations — A/B testing redirect variants, short-term campaign landing pages, or maintenance redirects that will be reversed.
Google typically processes 301 redirects and transfers link equity to the destination URL within a few weeks of the redirect being in place and crawled. Full authority consolidation may take two to three months as Googlebot recrawls all backlinks pointing to the old URL and re-evaluates the new URL's authority. During this period, rankings for the redirected pages may fluctuate. Monitoring in Search Console for crawl coverage and ranking changes in the weeks after implementing major redirects is important.